Release notes – v1.2.1

Backend

Symptom: docker push fails with blob unknown / repeated retries when pushing images built
with cache (layers reused from previous builds). All PUT /v2/.../blobs/uploads/... requests return
404.
Cause: The SFTP driver's ensureDir, PutContent, and Move functions checked if the group
folder existed on SFTP before creating directories. Any Stat error — including stale SSH connections
— was treated as "repository not found", returning 404 NAME_INVALID even for repos that already
exist with multiple tags.
Fix: Removed the strict group folder existence checks. The recursive directory creation that
already existed in ensureDir now handles all cases correctly — creating directories as needed
instead of failing.

Symptom: After the SFTP server restarts or SSH connections time out, all registry operations
fail until the backend is restarted.
Cause: The SFTP connection pool had no health check or reconnection logic. Broken clients were
returned from the pool indefinitely.
Fix: getClient() now performs a health check (Getwd()) before returning a client. If the
connection is dead, it automatically reconnects and logs [SFTP] Pool: stale connection detected, reconnecting....

Symptom: Intermittent digest mismatch or incomplete blob data when Docker pushes layers in
parallel across multiple connections.
Cause: The PATCH handler (uploadBlobData) sent the 202 Accepted response before closing
the file writer. If Docker sent the finalizing PUT on a different connection, the file could still be
unflushed.
Fix: File writer is now closed before sending the 202 response, ensuring data is fully
persisted to disk.

Area	Change	Type
Registry	Fix blob upload 404 on cached `docker push`	Fix
SFTP	Connection pool health check + auto-reconnect	Fix
Registry	Close chunk file before responding to PATCH	Fix